Datasheet

W0002-01
Decay Time
Target
Level
Input
Signal
Output
Signal
AGC
Gain
Attack
Time
TLV320AIC3110
www.ti.com SLAS647B –DECEMBER 2009–REVISED MAY 2012
Table 5-16. AGC Settings
(1)
(continued)
CONTROL REGISTER BIT FUNCTION
39 D3 (Read-only) ADC saturation flag
45 D6 (Read-only) Signal to level setting of noise threshold
86 D7 AGC enable
86 D6–D4 Target level
87 D7–D6 Hysteresis
87 D5–D1 Noise threshold
88 D6–D0 Maximum PGA applicable
89 D7–D0 Time constants (attack time)
90 D7–D0 Time constants (decay time)
91 D4–D0 Debounce time (noise)
92 D3–D0 Debounce time (signal)
93 D7–D0 (Read-only) Gain applied by AGC
Figure 5-2. AGC Characteristics
The AGC settings should be set based on user and system conditions, such as microphone selection and
sensitivity, acoustics (plastics) around the microphone which affect the microphone pattern, expected
distance and direction between microphone and sound source, acoustic background noise, etc.
One example of AGC code follows, but actual use of code should be verified based on application usage.
Note that the AGC code should be set up before powering up the ADC.
####################### AGC ENABLE EXAMPLE CODE #####################
## Switch to page 0
w 30 00 00
# Set AGC enable and Target Level = -10 dB
# Target level can be set lower if clipping occurs during speech
# Target level is adjusted considering Max Gain also
w 30 56 A0 # AGC hysteresis=DISABLE, noise threshold = -90dB
Copyright © 2009–2012, Texas Instruments Incorporated APPLICATION INFORMATION 27
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